Reevaluating the way we classify the diabetic foot: restructuring the diabetic foot risk classification system of the International Working Group on the Diabetic Foot

Maggot secretions skew monocyte-macrophage differentiation away from a pro-inflammatory to a pro-angiogenic type

BACKGROUND

Maggots of the blowfly Lucilia sericata are used for the treatment of chronic wounds. Earlier we reported maggot secretions to inhibit pro-inflammatory responses of human monocytes. The aim of this study was to investigate the effect of maggot secretions on the differentiation of monocytes into pro-inflammatory (MØ-1) and anti-inflammatory/pro-angiogenic macrophages (MØ-2) as these cells play a central role in wound healing.

METHODOLOGY/PRINCIPAL FINDINGS

Freshly isolated monocytes were incubated with secretions and GM-CSF or M-CSF for 6 days and then stimulated with LPS or LTA for 18 h. The expression of cell surface molecules and the levels of cytokines, chemokines and growth factors in supernatants were measured. Our results showed secretions to affect monocyte-macrophage differentiation leading to MØ-1 with a partial MØ-2-like morphology but lacking CD163, which is characteristic for MØ-2. In response to LPS or LTA, secretions-differentiated MØ-1 produced less pro-inflammatory cytokines (TNF-alpha, IL-12p40 and MIF) than control cells. Similar results were observed for MØ-2 when stimulated with low concentrations of LPS. Furthermore, secretions dose-dependently led to MØ-1 and MØ-2 characterized by an altered chemokine production. Secretions led to MØ-2, but not MØ-1, producing enhanced levels of the growth factors bFGF and VEGF, as compared to control cells. The expression of cell-surface receptors involved in LPS/LTA was enhanced by secretions, that of CD86 and HLA-DR down-regulated, while receptors involved in phagocytosis remained largely unaffected.

CONCLUSIONS

Maggot secretions skew the differentiation of monocytes into macrophages away from a pro-inflammatory to a pro-angiogenic type.

Automated ankle-brachial pressure index measurement by clinical staff for peripheral arterial disease diagnosis in nondiabetic and diabetic patients

OBJECTIVE

Peripheral arterial disease (PAD) is a prognostic marker in cardiovascular disease. The use of Doppler-measured ankle-brachial pressure index (Dop-ABI) for PAD diagnosis is limited because of time, required training, and costs. We assessed automated oscillometric measurement of the ankle-brachial pressure index (Osc-ABI) by nurses and clinical staff.

RESEARCH DESIGN AND METHODS

Clinical staff obtained Osc-ABI with an automated oscillometric device in 146 patients (83 with diabetes) at the time of Dop-ABI measurement and ultrasound evaluation.

RESULTS

Measurements were obtained in most legs (Dop-ABI 98%; Osc-ABI 95.5%). Dop- and Osc-ABI were significantly related in diabetic and nondiabetic patients with good agreement over a wide range of values. When Dop-ABI <or=0.90 was used as the gold standard for PAD, receiver operating characteristic curve analysis showed that PAD was accurately diagnosed with Osc-ABI in diabetic patients. When ultrasound was used to define PAD, Dop-ABI had better diagnostic performance than Osc-ABI in the whole population and in diabetic patients (P = 0.026). Both methods gave similar results in nondiabetic patients. The cutoff values for the highest sensitivity and specificity for PAD screening were between 1.0 and 1.1. Estimation of cost with the French medical care system fees showed a potential reduction by three of the screening procedures.

CONCLUSIONS

PAD screening could be improved by using Osc-ABI measured by clinical staff with the benefit of greater cost-effectiveness but at the risk of lower diagnostic performance in diabetic patients.

Effect of weight-bearing activity on foot ulcer incidence in people with diabetic peripheral neuropathy: feet first randomized controlled trial

BACKGROUND

Weight-bearing exercise has been contraindicated among people with diabetic peripheral neuropathy (DM+PN). However, recent cohort studies have suggested that daily weight-bearing activity is associated with lower risk for foot ulceration.

OBJECTIVE

The objective of this study was to determine the effect of a lower-extremity exercise and walking intervention program on weight-bearing activity and foot ulcer incidence in people with DM+PN.

DESIGN

This was an observer-blinded, 12-month randomized controlled trial.

SETTING

The settings were physical therapy offices in part 1 of the intervention and the community in part 2 of the intervention.

PARTICIPANTS

The participants were 79 individuals with DM+PN who were randomly assigned either to a control group (n=38) or an intervention group (n=41) group.

INTERVENTION

Intervention components included leg strengthening and balance exercises; a graduated, self-monitored walking program (part 1); and motivational telephone calls every 2 weeks (part 2). Both groups received diabetic foot care education, regular foot care, and 8 sessions with a physical therapist.

MEASUREMENTS

Total and exercise bout-related daily steps at baseline and at 3, 6, and 12 months were measured by accelerometers. Foot lesions/ulcers were photographed and classified by an independent panel of dermatologists. Use of adequate footwear was monitored.

RESULTS

At 6 months, bout-related daily steps increased 14% from baseline in the intervention group and decreased 6% from baseline in the control group. Although the groups did not differ statistically in the change in total daily steps, at 12 months steps had decreased by 13% in the control group. Foot ulcer rates did not differ significantly between groups.

CONCLUSION

Promoting weight-bearing activity did not lead to significant increases in foot ulcers. Weight-bearing activity can be considered following adequate assessment and counseling of patients with DM+PN.